During the last two years we have developed a powerful computer software system that permits: 1) rapid and accurate quantitation of protein distributions in two-dimensional gels and 2) rapid comparison of different gels to detect changes of radioactivity or stain density associated with all the individual protein and to detect the variation of location of related proteins. This proposal is to obtain funds to improve the software and to set up a new computer system with many peripheral devices especially oriented toward the analyses of 2-dimensional gel electropherograms. Experiments on applications of two-dimensional PAGE to problems of regulation of protein synthesis in eucaryotes (principally S. cerevisiae) are also outlined.